DEAR SIR: The Lancet article that shows in a bad light the consumption of meat foods, eggs and potatoes can, unless there is qualified rebuttal, have a disastrous effect on agriculture as we know it.I do not feel qualified to deal competently with health aspects that might arise from consumption of the products referred to, but I am in an authoritative position to deal with certain environmental aspects relating to the production of the sources of the preferred diets and of other crops grown in soil.